US20180246466A1 - Image forming apparatus - Google Patents
Image forming apparatus Download PDFInfo
- Publication number
- US20180246466A1 US20180246466A1 US15/898,054 US201815898054A US2018246466A1 US 20180246466 A1 US20180246466 A1 US 20180246466A1 US 201815898054 A US201815898054 A US 201815898054A US 2018246466 A1 US2018246466 A1 US 2018246466A1
- Authority
- US
- United States
- Prior art keywords
- cartridge
- image forming
- belt
- image
- drum
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- G03G21/00—Arrangements not provided for by groups G03G13/00 - G03G19/00, e.g. cleaning, elimination of residual charge
- G03G21/16—Mechanical means for facilitating the maintenance of the apparatus, e.g. modular arrangements
- G03G21/18—Mechanical means for facilitating the maintenance of the apparatus, e.g. modular arrangements using a processing cartridge, whereby the process cartridge comprises at least two image processing means in a single unit
- G03G21/1839—Means for handling the process cartridge in the apparatus body
- G03G21/1842—Means for handling the process cartridge in the apparatus body for guiding and mounting the process cartridge, positioning, alignment, locks
- G03G21/1853—Means for handling the process cartridge in the apparatus body for guiding and mounting the process cartridge, positioning, alignment, locks the process cartridge being mounted perpendicular to the axis of the photosensitive member
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- G03G15/00—Apparatus for electrographic processes using a charge pattern
- G03G15/01—Apparatus for electrographic processes using a charge pattern for producing multicoloured copies
- G03G15/0105—Details of unit
- G03G15/0121—Details of unit for developing
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- G03G15/00—Apparatus for electrographic processes using a charge pattern
- G03G15/04—Apparatus for electrographic processes using a charge pattern for exposing, i.e. imagewise exposure by optically projecting the original image on a photoconductive recording material
- G03G15/04036—Details of illuminating systems, e.g. lamps, reflectors
- G03G15/04045—Details of illuminating systems, e.g. lamps, reflectors for exposing image information provided otherwise than by directly projecting the original image onto the photoconductive recording material, e.g. digital copiers
- G03G15/04054—Details of illuminating systems, e.g. lamps, reflectors for exposing image information provided otherwise than by directly projecting the original image onto the photoconductive recording material, e.g. digital copiers by LED arrays
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- G03G15/00—Apparatus for electrographic processes using a charge pattern
- G03G15/06—Apparatus for electrographic processes using a charge pattern for developing
- G03G15/08—Apparatus for electrographic processes using a charge pattern for developing using a solid developer, e.g. powder developer
- G03G15/0822—Arrangements for preparing, mixing, supplying or dispensing developer
- G03G15/0865—Arrangements for supplying new developer
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- G03G15/00—Apparatus for electrographic processes using a charge pattern
- G03G15/14—Apparatus for electrographic processes using a charge pattern for transferring a pattern to a second base
- G03G15/16—Apparatus for electrographic processes using a charge pattern for transferring a pattern to a second base of a toner pattern, e.g. a powder pattern, e.g. magnetic transfer
- G03G15/1605—Apparatus for electrographic processes using a charge pattern for transferring a pattern to a second base of a toner pattern, e.g. a powder pattern, e.g. magnetic transfer using at least one intermediate support
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- G03G21/00—Arrangements not provided for by groups G03G13/00 - G03G19/00, e.g. cleaning, elimination of residual charge
- G03G21/16—Mechanical means for facilitating the maintenance of the apparatus, e.g. modular arrangements
- G03G21/18—Mechanical means for facilitating the maintenance of the apparatus, e.g. modular arrangements using a processing cartridge, whereby the process cartridge comprises at least two image processing means in a single unit
- G03G21/1803—Arrangements or disposition of the complete process cartridge or parts thereof
- G03G21/1814—Details of parts of process cartridge, e.g. for charging, transfer, cleaning, developing
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- G03G2215/00—Apparatus for electrophotographic processes
- G03G2215/06—Developing structures, details
- G03G2215/066—Toner cartridge or other attachable and detachable container for supplying developer material to replace the used material
Definitions
- the present disclosure relates to an image forming apparatus and is applicable to, for example, a laser beam printer, a facsimile machine, and a word processor employing the electrophotographic process.
- a light emitting diode (LED) printer includes a plurality of LEDs (hereinafter referred to as an LED array) juxtaposed in the axial direction of a photosensitive drum, and digitally controls the exposure timing of each element to form a latent image on the drum.
- the LED array includes small LEDs as light emitting elements and therefore enables downsizing of an apparatus.
- the LED array has a high degree of freedom in the arrangement in an image forming apparatus. For this reason, there have been proposed various cartridge replacement methods which have been difficult in a conventional exposure apparatus having a large-sized scanner unit (light scanning apparatus unit).
- an image forming apparatus is proposed, with which a cartridge including a photosensitive drum is replaced by opening and closing the top cover of the apparatus main body (Japanese Patent Application Laid-Open No. 2008-296379).
- a user replaces a cartridge by opening the top cover of the main body, vertically detaching the cartridge, and vertically attaching a new one. This process is intuitive, easy to understand, and has excellent usability.
- an image forming apparatus including a small-sized scanner (light scanning apparatus) is proposed, with which a cartridge including a photosensitive drum is replaced by opening and closing the top cover of the apparatus main body (Japanese Patent Application Laid-Open No. 2006-235656). Also in this apparatus, a user replaces a cartridge by opening the top cover of the main body, vertically detaching the cartridge, and vertically attaching a new one. This process is intuitive, easy to understand, and has excellent usability.
- an LED array disposed at the top cover In the apparatus discussed in Japanese Patent Application Laid-Open No. 2008-296379, an LED array disposed at the top cover. Therefore, an opening/closing operation at the time of cartridge replacement moves the LED array to degrade the positional accuracy between the photosensitive drum and the LED array, making high precision printing difficult. Further, since the LED array is disposed at the top cover of the main body, the user can touch exposure surfaces of LEDs possibly causing an exposure failure. Since the LED array is disposed at the top cover, at the time of cartridge replacement, the LED array is moved by a large amount and a load on the user is accordingly increased.
- the present disclosure is directed to further developing an image forming apparatus having a light emission unit including a plurality of light emitting elements.
- an image forming apparatus includes an apparatus main body to which a cartridge including a photosensitive drum is detachably attached, a light emission unit disposed close to an image bearing member, provided with a plurality of light emitting elements arranged in a rotational shaft direction of the image bearing member, and configured to irradiate the photosensitive drum with light to form a latent image, a regulation member configured to, when inserting the cartridge into the apparatus main body, regulate a movement in a direction perpendicularly intersecting with an insertion direction of the cartridge until an insertion of the cartridge is completed, and a belt configured to come in contact with the photosensitive drum during image formation.
- the light emission unit is disposed upstream from the belt in the insertion direction.
- a distance from a surface of the belt to a rotational shaft of the photosensitive drum is longer than a distance from the surface of the belt to an image forming position where light emitted by the light emission unit forms an image on a surface of the photosensitive drum.
- FIG. 1 is a perspective view illustrating an outer appearance an image forming apparatus according to a first example embodiment.
- FIG. 2 is a sectional view illustrating the image forming apparatus according to the first example embodiment.
- FIG. 3 is an enlarged sectional view illustrating an LED unit according to the first example embodiment.
- FIGS. 4A and 4B are perspective views illustrating the main body of the image forming apparatus according to the first example embodiment.
- FIGS. 5A, 5B, and 5C are perspective views illustrating image forming process parts of the image forming apparatus according to the first example embodiment.
- FIGS. 6A and 6B illustrate a pre-attachment state of a cartridge PM in the image forming apparatus according to the first example embodiment.
- FIGS. 7A and 7B illustrate a state of an attachment position of the cartridge PM in the image forming apparatus according to the first example embodiment.
- FIGS. 8A and 8B illustrate a door open state of the image forming apparatus according to the first example embodiment.
- FIGS. 9A and 9B illustrate a pull-out state of a cartridge PM in the image forming apparatus according to the first example embodiment.
- FIG. 10 illustrates a door open state (around a drive system) in the image forming apparatus according to the first example embodiment.
- FIGS. 11A and 11B are enlarged views illustrating a cartridge drive system of the image forming apparatus according to the first example embodiment.
- FIGS. 12A and 12B are enlarged sectional views illustrating cartridge drive system of the image forming apparatus according to the first example embodiment.
- FIGS. 13A, 13E, and 13C are enlarged sectional views illustrating cartridge replacement in the image forming apparatus according to the first example embodiment.
- FIG. 14 is a sectional view illustrating an image forming apparatus according to a modification of the first example embodiment.
- FIGS. 15A and 15B are sectional views illustrating cartridge replacement in the image forming apparatus according to the modification of the first example embodiment.
- FIGS. 16A and 16B are sectional views illustrating cartridge replacement in a configuration in which a development container and a drum are separate in the image forming apparatus according the modification of the first example embodiment.
- FIG. 17 is an enlarged sectional view illustrating the modification of the first example embodiment.
- FIG. 18 is a sectional view illustrating a non-contact charging corona system.
- FIG. 19 is a perspective view illustrating a cartridge of an image forming apparatus according to a second example embodiment.
- FIGS. 20A, 20B, and 20C are perspective views illustrating image forming process parts of the image forming apparatus according to the second example embodiment.
- FIGS. 21A and 21B illustrate a state of an attachment position of a cartridge PM in the image forming apparatus according to the second example embodiment.
- FIG. 22 illustrates a relation between a LED unit and a charging roller in the image forming apparatus according to the second example embodiment.
- FIGS. 23A, 23B, and 23C are sectional views illustrating cartridge replacement in the image forming apparatus according to the second example embodiment.
- FIG. 1 is a perspective view illustrating an outer appearance of an image forming apparatus 100 according to the present example embodiment.
- FIG. 2 is a sectional view illustrating the image forming apparatus 100 .
- the image forming apparatus 100 is a full color (4-color) LED printer using the electrophotographic process, having four cartridges P (PY, PM, PC, and PK) as a first to a fourth cartridge juxtaposed in a first direction.
- This image forming apparatus 100 capable of forming a full color (4-color) image or a monochrome image on a sheet-like recording medium (hereinafter referred to as a recording material) S based an electrical image signal output from an external host apparatus 400 ( FIG. 2 ) and input to a control unit 200 via an interface unit 300 .
- a recording material sheet-like recording medium
- the external host apparatus 400 is, for example, a personal computer, an image reader, or a facsimile machine as a communication partner.
- the control unit 200 ( FIG. 2 ) controls the electrophotographic image forming process of the image forming apparatus 100 , and transmits and receives various types of electrical information to/from the external host apparatus 400 .
- the control unit 200 performs processing on electrical information input from various types of process equipment and sensors, processing on instruction signals to various types of process equipment, predetermined initial sequence control, and sequence control for a predetermined electrophotographic image forming process.
- a side refers to the side on which a surface 31 is disposed
- a back side refers to the side opposite to the surface 31
- the anteroposterior direction refers to the direction from the back side toward the front side (anterior direction) of the image forming apparatus 100 , and the direction (posterior direction) opposite to the anterior direction.
- the right and left sides refer to the right and left of the image forming apparatus 100 , respectively, when viewed from the front side.
- the lateral direction refers to the direction from right to left (leftward direction), and the direction (rightward direction) opposite to the leftward direction.
- the top (top portion, upper portion, or upper side) and the bottom (bottom portion, lower portion, or lower side) refer to the top and bottom, respective in the vertical direction.
- the upward direction refers to the direction upwardly from the bottom, and a downward direction refers to the direction downwardly from the top.
- the longitudinal direction refers to the direction parallel to the rotational axis direction (axial direction) of an electrophotographic photosensitive member as an image bearing member on which a latent image is to be formed.
- the widthwise direction refers to a direction (orthogonal direction) perpendicularly intersecting with the longitudinal direction.
- One side of the longitudinal direction is the drive side, and the other end side thereof non-drive side.
- a right end side in the longitudinal direction is the drive side, and a left end side thereof is the non-drive side.
- an apparatus main body 100 a of the image forming apparatus 100 the four cartridges PY, PM, PC, and PK as a first to a fourth cartridge are juxtaposed in the horizontal direction (first direction) from the back to the front side of the apparatus main body 100 a, and attached at respective predetermined attachment positions.
- the image forming apparatus 100 employs what is called an in-line configuration or a tandem type configuration.
- the cartridges P are attached to positions at which the cartridges P can perform image forming operations, that is, positions at the time of image forming.
- the cartridges P according to the present example embodiment are instrumental to the image forming process for forming an image on a recording material S as image forming units, and are detachably attached to the apparatus main body 100 a of the image forming apparatus 100 .
- Each cartridge P according to the present example embodiment includes a drum-shaped electrophotographic photosensitive member (hereinafter referred to as a drum or photosensitive drum) 1 as an image bearing member on which a latent image is to be formed.
- the cartridge P is what is called an integrated process cartridge including a development unit 3 (including a developer container) as an electrophotographic image forming process unit which acts on the drum 1 .
- a charging device as a contact charging roller 2 is fixed to apparatus main body 100 a according to the present example embodiment.
- the development unit 3 is a contact type or noncontact type development unit including a developing roller 3 a as a developer bearing member for supplying the developer to the drum 1 to develop a latent image as a developer image, and a developer storage unit 3 b storing the developer.
- the color of the stored developer hereinafter referred to as toner
- toner The color of the stored developer (hereinafter referred to as toner) differs for each cartridge P
- the first cartridge PY including the development unit 3 storing yellow (Y) toner forms a Y color toner image on the surface of the drum 1 .
- the second cartridge PM including the development unit 3 storing magenta (M) toner forms an M color toner image on surface of the drum 1 .
- the third cartridge PC including the development unit 3 storing cyan (C) toner forms a C color toner image on the surface of the drum 1 .
- the fourth cartridge PK including the development unit 3 storing black (K) toner forms a K color toner image on the surface of the drum 1 .
- FIG. 3 is an enlarged sectional view illustrating the LED unit 11 .
- the LED unit 11 includes LED elements 11 a, gradient index type lenses 11 b, an electronic substrate 11 c, and an LED unit housing 11 d.
- a plurality of the LED elements 11 a is disposed in the longitudinal direction, and a plurality of the lenses 11 b is disposed corresponding to the LED elements 11 a.
- a plurality of the LED elements 11 a, the lenses 11 b, and the electronic substrate 11 c are held by the LED unit housing 11 d.
- An electrical conductive path is established between the electronic substrate 11 c and the control unit 200 .
- Operations for forming a latent image on the drum 1 are controlled by turning ON and OFF the light emission of each LED element 11 a according to image information for each color input from the external host apparatus 400 to the control unit 200 .
- Light of each LED element 11 a is condensed on each drum 1 through the lens 11 b to form a latent image.
- a primary transfer roller 17 is disposed below each of the cartridges PY, PM, PC, and PK to face each cartridge P.
- the primary transfer roller 17 serves as transfer member for primarily transferring a toner image on the drum 1 to an intermediate transfer member (described below).
- the toner image primarily transferred to the intermediate transfer member is secondarily transferred to the recording material S by a secondary transfer roller 27 .
- An intermediate transfer unit 12 illustrated in FIG. 2 includes a dielectric flexible endless belt (an intermediate transfer belt or a belt) 13 as an intermediate transfer member (second image bearing member, i.e., intermediate recording medium).
- the intermediate transfer unit 12 further includes a drive roller 14 , an auxiliary roller 15 , and a tension roller 16 for circularly moving the belt 13 entrained therearound in a stretched way.
- the drive roller 14 and the auxiliary roller 15 are disposed on the back side within the apparatus main body 100 a.
- the tension roller 16 is disposed on the front side within the apparatus main body 100 a.
- the undersurface of each drum 1 is in contact with the upper surface of the upper belt portion of the belt 13 .
- the primary transfer roller is disposed to face the drum 1 of each cartridge across the upper belt portion.
- a nip portion between the drum 1 and the belt 13 is a primary transfer nip portion T 1 .
- a secondary transfer roller 27 is in contact with the drive roller across the belt 13 .
- a nip portion between the secondary transfer roller 27 and the belt 13 is a secondary transfer nip portion T 2 .
- the sheet feed unit 18 feeds the recording materials S one by one to the intermediate transfer unit 12 .
- the sheet feed unit 18 includes a paper feed tray 19 for storing the stacked recording materials a feed roller 20 , a separation pad 21 , and a registration roller pair 22 .
- the paper feed tray 19 can be freely loaded from the front side of the apparatus main body 100 a (front loading).
- a fixing apparatus 23 as a fixing unit and roller pair 24 for discharging the recording material S.
- the fixing apparatus 23 applies heat and pressure to the recording material S which bears a toner image transferred thereto, to fix the toner image to the recording material S.
- the fixing apparatus 23 includes a fixing film assembly 23 a and a pressure roller 23 b, and the discharging roller pair 24 includes discharging rollers 24 a and 24 b.
- a door 30 as an opening/closing member for an upper opening portion of the apparatus main body 100 a is disposed at the upper portion of the apparatus main body 100 a.
- the door 30 is rotatable around predetermined position as a fulcrum in the direction (first direction) in which a plurality of the cartridges P is juxtaposed.
- the user can detachably attach the cartridges to the apparatus main body 100 a through the opening portion.
- a part of the upper surface of the door 30 functions as a discharge tray 25 .
- the drum is driven to rotate at a predetermined control speed in the direction (counterclockwise direction) indicated by the arrow illustrated in FIG. 2 .
- the belt 13 is also driven to rotate at a speed corresponding to the speed of the drum 1 in the clockwise direction indicated by the arrow (in a forward direction of the rotation of the drum 1 ).
- the charging roller 2 uniformly charges the surface of the drum 1 to a predetermined polarity and potential at predetermined control timing, in synchronization with the driving. Then, the LED unit 11 irradiates the surface of the drum 1 with light for exposure, according to an image signal for each color. In this way, a static electricity latent image (latent image) according to the image signal of the corresponding color is formed on the surface of each drum 1 .
- the formed latent image is developed as toner image (developer image) by the development unit 3 .
- a Y color toner image corresponding to the Y color component of a full color image is formed on the drum 1 of the first cartridge PY through the above-described electrophotographic image forming process operations.
- the toner image primarily transferred to the belt 13 .
- An M color image corresponding the M color component of the full color image is formed on the drum 1 of the second cartridge PM.
- the toner image primarily transferred to the Y color toner image already transferred on the belt 13 in a superimposed way.
- a C color toner image corresponding to the C color component of the full color image is formed on the drum 1 of third cartridge PC.
- the toner image primarily transferred to the Y+M color toner image already transferred on the belt 13 in a superimposed way.
- a K color toner image corresponding to the K color component of the full color image is formed on the drum 1 of the fourth cartridge PK.
- the toner image is primarily transferred to the Y+M+C color toner image already transferred on the belt 13 in a superimposed way.
- the feed roller 20 is driven at predetermined control timing.
- the feed roller 20 and the separation pad 21 collaborate to separate and feed one sheet of the recording materials S stacked in the paper feed tray 19 .
- the registration roller pair 22 guides the recording material to the secondary transfer nip portion T 2 at predetermined control timing. In this way, in a process in which the recording material S is conveyed through the secondary transfer nip portion T 2 in a nipped state, the 4-color superimposed toner image on the belt 13 is collectively transferred to the surface of the recording material S.
- the recording material S is separated from the surface of the belt 13 , guided to the fixing apparatus 23 through the conveyance path, and applied with heat and pressure at the fixing nip portion N. In this way, toner images of respective colors are mixed and fixed to the recording material S. After that, the recording material S exits the fixing apparatus 23 and is discharged onto the discharge tray 25 as a full color image by the discharging roller pair 24 . After the recording material P is separated from the belt 13 , secondary transfer residual toner remaining on the surface of the belt 13 is removed by a cleaning unit 26 .
- FIGS. 4A and 4B illustrate the apparatus main body 100 a when viewed from the left-hand side and the right-hand side, respectively (the exterior and drive system are not illustrated).
- the apparatus main body 100 a is provided with a left substrate 101 ( FIG. 4A ) and a right substrate 102 ( FIG. 4B ) for supporting each roller and each unit.
- the left substrate 101 is provided with a left holder 103
- the right substrate 102 is provided with a right holder 104 .
- the right and the left holders 103 and 104 are integrally formed.
- the left and the right holders 103 and 104 support the cartridges P, the LED units 11 , the charging rollers 2 , and the intermediate transfer unit 12 as identical holding members, and determine the positions of these members relative to the apparatus main body and each unit.
- FIG. 5A illustrates only the left and the right holders 103 and 104
- FIG. 5B illustrates a state where the LED units 11 and the charging rollers 2 are additionally disposed in the state illustrated in FIG. 5A
- FIG. 5C illustrates a state where the intermediate transfer unit 12 is additionally disposed in the state illustrated in FIG. 5B
- the LED units 11 are fixed to the holes 104 a of the right holder 104 corresponding to the four cartridges PY, PM, PC, and PK.
- the charging rollers 2 are rotatably supported by the holes 104 b of the right holder 104 .
- the left holder 103 is also provided with hole shapes (not illustrated) similar to those of the right holder 104 . These shapes also fix the LED units 11 and rotatably support the charging rollers 2 .
- the drive roller 14 and the tension roller 16 are rotatably supported by the holes 104 c and 104 d ( FIG. 5A ) on the right holder 104 , respectively. Similar to the LED units 11 and the charging rollers 2 , the drive roller 14 and the tension roller 16 are also supported by the left holder 103 .
- FIGS. 6A and 6B illustrate a state before only a cartridge PM is attached to the right holder 104
- FIGS. 7A to 7C illustrate a state after the cartridge PM has been attached to the right holder 104
- FIGS. 6A and 7A are perspective views illustrating the cartridge PM and the right holder 104
- FIGS. 6B and 7B are sectional views illustrating the cartridge PM and the right holder 104 illustrated in FIGS. 6A and 7A , respectively.
- a method for holding a cartridge P will be described below by using only the cartridge PM and the right holder 104 . Similar to the LED units 11 , the charging rollers 2 , and the intermediate transfer unit 12 , the cartridge PM and the right holder 104 are also supported by the left holder 103 . The cartridges PY, PC, and PK are supported in a similar way to the cartridge PM.
- the right holder 104 is provided with U-shaped slots for positioning and inserting/extracting (attaching/detaching) a cartridge P. These slots respectively correspond to a drum shaft 1 R of the drum 1 held by the cartridge PM and a boss 3 R of the development unit 3 of the cartridge PM. Two U-shaped slots for positioning and inserting/extracting (attaching/detaching) a cartridge P are provided for each color.
- the right holder 104 is also provided with another U-shaped slot for placing the shaft of the developing roller 3 a. This U-shaped slot is not used for positioning but for connecting to and disconnecting from the drive system (described below).
- the drum shaft 1 R of the drum 1 held by the cartridge PM is rotatably supported by a curved surface portion 104 f of the U-shaped slot of the right holder 104 , thus determining the position of the drum 1 .
- a U-shaped slot as an attachment/detachment passage is formed on the right holder 104 as an attachment/detachment passage forming member.
- the boss 3 R of the development unit 3 of the cartridge PM fits into regulation portions 104 e as straight portions of the U-shaped slot of the right holder 104 , thus regulating the rotation of the center of the drum 1 in the cartridge PM.
- the above-described configuration determines the position of the cartridge PM relative to the apparatus main body 100 a.
- the positions of the cartridges P, the LED units 11 , the charging rollers 2 , and the intermediate transfer unit 12 are determined only by the left and the right holders 103 and 104 .
- high precision positioning is achieved because the members for holding positioning parts for the cartridges P, the LED units 11 , the charging rollers 2 , and the intermediate transfer unit 12 related to the image forming process are common (same).
- the LED units 11 do not move as in the apparatus discussed in the Japanese Patent Application Laid-Open No. 2008-296379. Therefore, there arises no positional accuracy degradation due to parts abrasion during movement, thus enabling high precision printing. Since the LED units 11 are not installed on a cover to opened to replace a cartridge as in the apparatus discussed in the Japanese Patent Application Laid-Open No. 2008-296379 but installed inside the apparatus main body 100 a, the user can hardly touch the exposure surfaces of the LED units 11 and there is no possibility of poor exposure.
- the apparatus main body 100 a is provided with a method (not illustrated) for detecting the amount of remaining developer for each cartridge.
- the control unit 200 compares the detected value with a preset threshold value for life notification or warning. When the detected value of the developer remaining amount is smaller than the threshold value for a certain cartridge, the control unit 200 displays the life notification or warning for the cartridge on a display unit (not illustrated). This prompts a user to ready a new cartridge in preparation for replacement or replace the cartridge to maintain the quality of output images.
- FIG. 8A illustrates a state where the door 30 is opened
- FIG. 8B is a sectional view the state illustrated in FIG. 8A
- FIG. 9A illustrates a state where a cartridge PM is slightly pulled out in the state illustrated in FIG. 8A
- FIG. 9B is a sectional view illustrating the state illustrated in FIG. 9A
- the user holds a handle 30 a and rotates the door 30 in the R 1 direction around a door rotational axis 30 b to open the door 30 , as illustrated in FIGS. 8A and 8B .
- the user pulls the cartridge PM in the Al direction to take it out from the inside of the apparatus main body 100 a and inserts new cartridge PM in the A 2 direction to replace the cartridge.
- the drive of the drum 1 and the developing roller 3 a is disconnected in synchronization with the opening.
- the drive is accordingly connected.
- the cartridge PM can be easily detached from the apparatus main body 100 a.
- FIG. 10 illustrates only the door 30 when opened, the cartridges P, and drive systems around the cartridges P.
- FIGS. 11A and 11B are enlarged views illustrating the drive system around the cartridge PK
- FIGS. 12A and 12B are sectional views illustrating the drive system illustrated FIGS. 11A and 11B .
- FIGS. 11A and 12A illustrate a state where the door 30 is closed
- FIGS. 11B and 12B illustrate a state where the door 30 is opened.
- link arms 111 and 112 are rotatably supported and are connected to links 121 and 122 , respectively.
- the links 121 and 122 are supported movably only in the longitudinal direction of the main body 100 a (a supporting method is not illustrated).
- the links 121 and 122 are connected to link arms 131 and 132 , respectively.
- the link arms 131 and 132 are rotatably supported by coupling cams 141 and 142 , respectively.
- the coupling cams 141 and 142 contact coupling cams 151 and 152 , respectively.
- Drive gears 161 and 162 are rotatably disposed at the center of the coupling cams 141 and 151 and the center of the coupling cams 142 and 152 , respectively.
- the drive gear 161 drives the drum 1
- the drive gear 162 drives the developing roller 3 a
- a drive gear 163 drives the charging roller 2 (a method for supporting drive gears is not illustrated).
- the drive gears 161 and 162 are pressed in the B direction by springs (not illustrated), and the urging forces thereof can also be transmitted to the coupling cams 151 and 152 , respectively.
- the coupling cams 142 and 152 on the side of the developing roller 3 a are configured in a similar way to the side of the drum 1 , and redundant descriptions thereof will be omitted.
- the driving force is not transmitted to the developing roller 3 a.
- the driving force to the drum 1 and the developing roller 3 a can be disconnected, allowing the user to replace a cartridge P.
- FIGS. 13A to 13C are enlarged sectional views illustrating a state where a cartridge P is replaced. While FIGS. 13A to 13C illustrate a relation between cartridge P and the right holder 104 , the left holder 103 has a similar configuration.
- FIG. 13A illustrates a state before a cartridge P is attached to the attachment position
- FIG. 13E illustrates a state where the cartridge P is regulated to move only in two directions by the regulation portions 104 e and 104 g
- FIG. 13C illustrates a state where the cartridge P has been attached to the attachment position.
- the boss 3 R of the cartridge P and the drum shaft 1 R come in contact with the regulation portions 104 e and 104 g of the right holder 104 , respectively (the state illustrated in FIG. 13B ).
- the cartridge P becomes movable only in the vertical direction illustrated in FIG. 13C .
- h 1 >h 2 a relation “h 1 >h 2 ” is satisfied, where h 1 denotes the height from the belt 13 ( FIG. 2 ) to the drum 1 , and h 2 denotes the height from the belt 13 to the LED unit 11 . Therefore, when h 1 ⁇ h 2 , the movement of the cartridge P in the B direction perpendicularly intersecting with the extraction direction A 1 and the insertion direction A 2 is regulated by the regulation portions 104 e and 104 g until the insertion of the cartridge P is completed. Thus, the drum 1 can be prevented from contacting the LED unit 11 , so that the surface of the drum 1 can be prevented from being damaged, and the LED unit 11 can be prevented from breaking down.
- the LED unit 11 is disposed at a position where the LED unit 11 does not overlap with the attachment/detachment locus of the drum 1 in the B direction perpendicularly intersecting with the extraction direction A 1 and the insertion direction A 2 of the cartridge P. More specifically, in a state where the insertion of the cartridge P into the apparatus main body 100 a is completed, the rotational shaft of the drum 1 is disposed, in the insertion direction A 2 of the cartridge P, downstream from the image forming position where light emitted by the LED unit 11 forms an image the surface of the drum 1 .
- the LED unit 11 is disposed, in the insertion direction A 2 , upstream from the belt 13 , it becomes possible to prevent the drum 1 from contacting the LED unit 11 , prevent the surface of the drum from being damaged, and prevent the LED unit 11 from breaking down.
- the LED unit 11 is disposed at a position where the LED unit 11 does not overlap with attachment/detachment locus of the drum 1 in the B directions Therefore, a condition “h 3 ⁇ h 4 ” is satisfied in a state where the attachment the cartridge P is completed, as illustrated in FIG.
- h 3 denotes the height of the rotational shaft of the drum 1 from the belt 13
- h 4 denotes the height of the image forming position (where light from the LED unit 11 forms an image on the drum 1 ) from the belt 13
- the height refers to the distance from the surface of the belt 13 to the rotational shaft or the image forming position of the drum 1 in the normal direction on the surface of the belt 13 .
- This configuration can be applied to positioning in which the LED unit 11 is abutted against and brought into contact with the drum 1 by using a spring (not illustrated). Even in such a configuration, the following effects are obtained: When the rotational shaft of the drum 1 is disposed, in the insertion direction A 2 of the cartridge P (a direction from the surface of the belt 13 toward the drum 1 in the normal direction of the belt 13 ), downstream from the image forming position where light emitted by the LED unit 11 forms an image on the surface of the drum 1 , the LED unit 11 does not contact the portion of the drum 1 having the largest radius at time of inserting or extracting a cartridge P.
- regulating the cartridge P to a certain extent improves usability.
- the user starts the insertion of the cartridge P into the apparatus main body 100 a (the state illustrated in FIG. 13A )
- the user can insert the cartridge P while freely moving it.
- the position of the cartridge P can be guided to the attachment position (the state illustrated in FIG. 13B ).
- the cartridge P is stopped at the attachment position where an image is formed on the drum (the state illustrated in 13 C). Therefore, according to the present example embodiment, it is possible to achieve high usability and a configuration for inserting/extracting (attaching/detaching) a cartridge P without causing a damage to the cartridge P and the LED unit 11 when inserting a cartridge P.
- the present example embodiment enables the apparatus downsizing by disposing an LED array as a light emission unit close to the photosensitive drum 1 . This because the LED array produces a lower light quantity than a scanner, and a gradient index type lens for collecting LED light has a short focal length.
- high precision printing can be achieved by fixing the light emission unit to the inside of the apparatus main body 100 a, unlike the apparatus discussed in Japanese Patent Application Laid-Open No. 2008-296379.
- high precision printing can be guaranteed by such positioning that the cartridge P does not hit the light emission unit fixed to the apparatus main body 100 a when attaching/detaching a cartridge P including the drum 1 .
- the cartridge (first cartridge) including the drum 1 does not include the charging roller 2 .
- the cartridge (first cartridge) including the drum 1 includes the charging roller 2 .
- Other configurations are similar to those according to the first example embodiment.
- FIG. 19 is a perspective view illustrating a cartridge P having a configuration according to the present example embodiment. Similar to the first example embodiment, the cartridge P is provided with the drum 1 and the developing roller 3 a. The cartridge P is also provided with the charging roller 2 as an additional member. More specifically, the charging roller 2 is rotatably supported in a development unit 301 including the developing roller 3 a, and is rotatably driven along with the rotation of the drum 1 .
- FIG. 20A illustrates only left and the right holders 303 and 304
- FIG. 20B illustrates a state where the LED units 11 are disposed in addition
- FIG. 20C illustrates a state where the intermediate transfer unit 12 is disposed in addition to FIG. 20B
- the left and the right holders 303 and 304 are disposed on the left and the right substrates 101 and 102 , respectively.
- the LED units 1 are fixed to the holes 304 a of the right holder 304 corresponding to the four cartridges PY, PM, PC, and PK. Similar to the right holder 304 , the left holder 303 is also provided with hole shapes (not illustrated), and the LED units 11 are fixed to the left holder 303 .
- the drive roller 14 and the tension roller 16 are rotatably supported in the holes 304 c and 304 d of the right holder 304 . Similar to the LED units 11 , the drive roller 14 and the tension roller 16 are also supported in the left holder 303 .
- FIGS. 21A and 12B illustrate a state where only a cartridge PM is attached to the right holder 304 .
- FIG. 21A is a perspective view illustrating the cartridge PM and the right holder 304
- FIG. 21B is a sectional view illustrating the cartridge PM and the right holder 304 illustrated in FIG. 21A .
- the method for supporting the cartridge P will be described below based only on the cartridge PM and the right holder 304 .
- the cartridge PM is similarly supported in the left holder 303 .
- the cartridges PY, PC, and PK are supported in a way similar to the cartridge PM.
- the right holder 304 is provided with U-shaped slots for positioning and attaching/detaching a cartridge P corresponding to the drum shaft 1 R of the drum 1 held in the cartridge PM and a boss 301 R of the development unit 301 of the cartridge PM. Two U-shaped slots for positioning and inserting/extracting (attaching/detaching) a cartridge are provided for each color.
- the right holder 304 is also provided with another U-shaped slot for placing the shaft of the developing roller 3 a. This U-shaped slot is not used for positioning but for connecting to and disconnecting from the drive system.
- the drum shaft 1 R of the drum held by the cartridge PM is rotatably supported in curved surface portion 304 f of the U-shaped slot of the right holder 304 , thus determining the position of the drum 1 .
- the boss 301 R of the development unit 301 of the cartridge PM fits into regulation portions 304 e as straight portions of the U-shaped slot of the right holder 304 , thus regulating the rotation of the center of the drum 1 in the cartridge PM.
- the cartridge P holds the charging roller 2 .
- the charging roller 2 needs to be disposed on the upstream side of the LED unit 11 in contact with the drum 1 . Since the LED unit 11 needs to be disposed close to the drum 1 as described above, the LED unit 11 and the charging roller 2 are disposed in a positional relation as illustrated in FIG. 22 .
- FIG. 22 illustrates an area where light of the LED unit 11 is projected on the belt 13 , and the charging roller 2 is disposed within the area.
- the charging roller 2 exists as a part of a charge member in the area on which the light of the LED unit 11 is projected.
- the cartridge P cannot inserted/extracted (attached/detached) in one direction as in first example embodiment. Therefore, it is necessary to insert the cartridge P into the apparatus main body 100 a while getting the charging roller 2 into under the LED unit 11 .
- FIGS. 23A to 23C are enlarged sectional views illustrating a state where the cartridge P is replaced. While FIGS. 23A to 23C illustrate a relation between the cartridge P and the right holder 304 , the left holder 303 also has a similar configuration.
- FIG. 23A illustrates a state before a cartridge P is attached to the attachment position
- FIG. 23B illustrates a state where the cartridge P is regulated to move only 1 n two directions by regulation portions 304 e and 304 g
- FIG. 23C illustrates a state where the cartridge P has been attached to the attachment position.
- an attachment/detachment passage has the vertical direction (second direction) as an attachment/detachment direction.
- the boss 301 R of the cartridge P and the drum shaft 1 R come in contact with the regulation portions 304 e and 304 g of the right holder 304 , respectively (the state illustrated in FIG. 23B ).
- the cartridge P becomes movable only in the J and K directions illustrated in FIG. 23B .
- the right holder 304 is provided with second area as an attachment/detachment passage connecting with the first area.
- the second area has a direction (third direction) intersecting with the vertical direction (second direction) as an attachment/detachment direction.
- the insertion/extraction direction of the cartridge P is regulated using the regulation portions 304 e and 304 g in this way, so that the drum 1 and the charging roller 2 can be prevented from contacting the LED unit 11 .
- This regulation prevents the surfaces of the drum 1 and the charging roller 2 from being damaged and prevents the LED unit 11 from breaking down.
- regulating the cartridge P to a certain extent improves usability.
- the user starts the insertion of the cartridge P into the apparatus main body 100 a (the state illustrated in FIG. 22A )
- the user can insert the cartridge P while freely moving it.
- the position of the cartridge P can be guided to the attachment position (the state illustrated in FIG. 23B ).
- the cartridge P is stopped at the attachment posit on where an image is formed on the drum 1 (the state illustrated in FIG. 23C ). Therefore, according to the present example embodiment, is possible achieve a configuration showing high usability for inserting/extracting a cartridge P without causing a damage to the cartridge P and the LED unit 11 when inserting a cartridge P.
- a charge member is integrally formed with a cartridge P to limit the locus of the photosensitive drum 1 and the charging roller 2 . This limitation prevents them from contacting the LED unit 11 , so that the insertion/extraction (attachment/detachment) of a cartridge P can be achieved.
- This configuration makes it possible to provide an image forming apparatus capable of achieving both apparatus downsizing and high precision printing by using a light emission unit having a plurality of light emitting elements while an opening/closing member is disposed at an upper portion of the apparatus in a vertical direction. More specifically, compared with case where a light scanning apparatus (scanner) is used, the present example embodiment enables apparatus downsizing by disposing an LED array as a light emission unit close to the photosensitive drum 1 . High precision printing is enabled by fixing the light emission unit to the inside of the apparatus main body 100 a, unlike the apparatus discussed in Japanese Patent Application Laid-Open No. 2008-296379.
- high precision printing can guaranteed by positioning the cartridge P such that it does not hit the light emission unit fixed to the apparatus main body 100 a when attaching/detaching a cartridge P which includes the drum 1 and the charging roller 2 .
- the image forming apparatuses include the transfer rollers 17 for primarily transferring toner images to an intermediate transfer member (intermediate transfer belt), and the secondary transfer roller 27 for secondarily transferring to a recording material the toner image primarily transferred to the intermediate transfer member.
- An image forming apparatus may not include the secondary transfer roller 27 as illustrated in FIG. 14 , and may directly transfer toner images to a recording material conveyed by a conveyance belt, by using the transfer rollers 17 . While this configuration is applicable not only to the first example embodiment but also to the second example embodiment, a modification of the first example embodiment will be illustrated in FIG. 14 as a representative.
- the drive roller 14 and the tension roller 16 move a conveyance belt 213 in circles in a stretched way.
- the recording material S conveyed from the sheet feed unit 18 is conveyed from the front side to the back side by the conveyance belt 213 .
- toner images are sequentially transferred from the four cartridges 2 to the recording material S, thus forming an image.
- the process of forming a toner image on the drum 1 of a cartridge P is similar to the process illustrated in FIG. 2 . Similar to the recording material S in FIG. 2 , the recording material S with toner images transferred thereto passes through the fixing apparatus 23 and the discharging roller pair 24 , and then is stacked on the discharge tray 25 . As illustrated in FIGS. 15A and 15B , the modification illustrated in FIG. 14 allows the user to perform cartridge replacement in the same way as illustrated in FIGS. 9A and 9B .
- the drum 1 and a development unit 203 are integrally formed as a process cartridge, the present disclosure is not limited thereto. More specifically, as illustrated in FIGS. 16A, 16B, and 17 , the second cartridge including the development unit 203 may be separated relative to the first cartridge including the drum 1 .
- a boss 203 R of the development unit 203 is rotatably supported by a curved surface portion 204 f of the U-shaped slot of a right holder 204 .
- the urging force of a spring 250 disposed in the apparatus main body 100 a causes a pressing cam 251 to press development unit 203 to the left. Since the development unit 203 is pressed by the urging force of the spring 250 , the developing roller 3 a can be pressed onto the drum 1 .
- the pressing cam 251 is configured to be movable only in the lateral direction illustrated in FIG. 17 .
- the pressing cam 251 presses the development unit 203 .
- the pressing cam 251 stops pressing the development unit 203 .
- the left holder (not illustrated) is also configured in a similar way to the above-described right holder 204 .
- a corona charging 222 can also be used as a charge member, which does not contact the drum 1 , as illustrated in FIG. 18 .
- an LED is used as a light emitting element
- other light emitting elements can also be used.
Abstract
Description
- The present disclosure relates to an image forming apparatus and is applicable to, for example, a laser beam printer, a facsimile machine, and a word processor employing the electrophotographic process.
- As a conventional configuration for exposing a photosensitive drum to light, a light emitting diode (LED) printer includes a plurality of LEDs (hereinafter referred to as an LED array) juxtaposed in the axial direction of a photosensitive drum, and digitally controls the exposure timing of each element to form a latent image on the drum. The LED array includes small LEDs as light emitting elements and therefore enables downsizing of an apparatus. The LED array has a high degree of freedom in the arrangement in an image forming apparatus. For this reason, there have been proposed various cartridge replacement methods which have been difficult in a conventional exposure apparatus having a large-sized scanner unit (light scanning apparatus unit).
- For example, an image forming apparatus is proposed, with which a cartridge including a photosensitive drum is replaced by opening and closing the top cover of the apparatus main body (Japanese Patent Application Laid-Open No. 2008-296379). In this apparatus, a user replaces a cartridge by opening the top cover of the main body, vertically detaching the cartridge, and vertically attaching a new one. This process is intuitive, easy to understand, and has excellent usability.
- Further, an image forming apparatus including a small-sized scanner (light scanning apparatus) is proposed, with which a cartridge including a photosensitive drum is replaced by opening and closing the top cover of the apparatus main body (Japanese Patent Application Laid-Open No. 2006-235656). Also in this apparatus, a user replaces a cartridge by opening the top cover of the main body, vertically detaching the cartridge, and vertically attaching a new one. This process is intuitive, easy to understand, and has excellent usability.
- In the apparatus discussed in Japanese Patent Application Laid-Open No. 2008-296379, an LED array disposed at the top cover. Therefore, an opening/closing operation at the time of cartridge replacement moves the LED array to degrade the positional accuracy between the photosensitive drum and the LED array, making high precision printing difficult. Further, since the LED array is disposed at the top cover of the main body, the user can touch exposure surfaces of LEDs possibly causing an exposure failure. Since the LED array is disposed at the top cover, at the time of cartridge replacement, the LED array is moved by a large amount and a load on the user is accordingly increased.
- The present disclosure is directed to further developing an image forming apparatus having a light emission unit including a plurality of light emitting elements.
- According to an aspect of the present disclosure, an image forming apparatus includes an apparatus main body to which a cartridge including a photosensitive drum is detachably attached, a light emission unit disposed close to an image bearing member, provided with a plurality of light emitting elements arranged in a rotational shaft direction of the image bearing member, and configured to irradiate the photosensitive drum with light to form a latent image, a regulation member configured to, when inserting the cartridge into the apparatus main body, regulate a movement in a direction perpendicularly intersecting with an insertion direction of the cartridge until an insertion of the cartridge is completed, and a belt configured to come in contact with the photosensitive drum during image formation. The light emission unit is disposed upstream from the belt in the insertion direction. In a state where the insertion of the cartridge into the apparatus main body is completed, in a normal direction to the surface of the belt, a distance from a surface of the belt to a rotational shaft of the photosensitive drum is longer than a distance from the surface of the belt to an image forming position where light emitted by the light emission unit forms an image on a surface of the photosensitive drum.
- Further features and aspects of the present disclosure will become apparent from the following description of various example embodiments with reference to the attached drawings.
-
FIG. 1 is a perspective view illustrating an outer appearance an image forming apparatus according to a first example embodiment. -
FIG. 2 is a sectional view illustrating the image forming apparatus according to the first example embodiment. -
FIG. 3 is an enlarged sectional view illustrating an LED unit according to the first example embodiment. -
FIGS. 4A and 4B are perspective views illustrating the main body of the image forming apparatus according to the first example embodiment. -
FIGS. 5A, 5B, and 5C are perspective views illustrating image forming process parts of the image forming apparatus according to the first example embodiment. -
FIGS. 6A and 6B illustrate a pre-attachment state of a cartridge PM in the image forming apparatus according to the first example embodiment. -
FIGS. 7A and 7B illustrate a state of an attachment position of the cartridge PM in the image forming apparatus according to the first example embodiment. -
FIGS. 8A and 8B illustrate a door open state of the image forming apparatus according to the first example embodiment. -
FIGS. 9A and 9B illustrate a pull-out state of a cartridge PM in the image forming apparatus according to the first example embodiment. -
FIG. 10 illustrates a door open state (around a drive system) in the image forming apparatus according to the first example embodiment. -
FIGS. 11A and 11B are enlarged views illustrating a cartridge drive system of the image forming apparatus according to the first example embodiment. -
FIGS. 12A and 12B are enlarged sectional views illustrating cartridge drive system of the image forming apparatus according to the first example embodiment. -
FIGS. 13A, 13E, and 13C are enlarged sectional views illustrating cartridge replacement in the image forming apparatus according to the first example embodiment. -
FIG. 14 is a sectional view illustrating an image forming apparatus according to a modification of the first example embodiment. -
FIGS. 15A and 15B are sectional views illustrating cartridge replacement in the image forming apparatus according to the modification of the first example embodiment. -
FIGS. 16A and 16B are sectional views illustrating cartridge replacement in a configuration in which a development container and a drum are separate in the image forming apparatus according the modification of the first example embodiment. -
FIG. 17 is an enlarged sectional view illustrating the modification of the first example embodiment. -
FIG. 18 is a sectional view illustrating a non-contact charging corona system. -
FIG. 19 is a perspective view illustrating a cartridge of an image forming apparatus according to a second example embodiment. -
FIGS. 20A, 20B, and 20C are perspective views illustrating image forming process parts of the image forming apparatus according to the second example embodiment. -
FIGS. 21A and 21B illustrate a state of an attachment position of a cartridge PM in the image forming apparatus according to the second example embodiment. -
FIG. 22 illustrates a relation between a LED unit and a charging roller in the image forming apparatus according to the second example embodiment. -
FIGS. 23A, 23B, and 23C are sectional views illustrating cartridge replacement in the image forming apparatus according to the second example embodiment. - Example embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.
- A first example embodiment will be described below.
FIG. 1 is a perspective view illustrating an outer appearance of animage forming apparatus 100 according to the present example embodiment.FIG. 2 is a sectional view illustrating theimage forming apparatus 100. Theimage forming apparatus 100 is a full color (4-color) LED printer using the electrophotographic process, having four cartridges P (PY, PM, PC, and PK) as a first to a fourth cartridge juxtaposed in a first direction. Thisimage forming apparatus 100 capable of forming a full color (4-color) image or a monochrome image on a sheet-like recording medium (hereinafter referred to as a recording material) S based an electrical image signal output from an external host apparatus 400 (FIG. 2 ) and input to acontrol unit 200 via aninterface unit 300. - The
external host apparatus 400 is, for example, a personal computer, an image reader, or a facsimile machine as a communication partner. - The control unit 200 (
FIG. 2 ) controls the electrophotographic image forming process of theimage forming apparatus 100, and transmits and receives various types of electrical information to/from theexternal host apparatus 400. Thecontrol unit 200 performs processing on electrical information input from various types of process equipment and sensors, processing on instruction signals to various types of process equipment, predetermined initial sequence control, and sequence control for a predetermined electrophotographic image forming process. - In the following descriptions of the
image forming apparatus 100, a side (front face side) refers to the side on which asurface 31 is disposed, and a back side (rear face side) refers to the side opposite to thesurface 31. The anteroposterior direction refers to the direction from the back side toward the front side (anterior direction) of theimage forming apparatus 100, and the direction (posterior direction) opposite to the anterior direction. The right and left sides refer to the right and left of theimage forming apparatus 100, respectively, when viewed from the front side. The lateral direction refers to the direction from right to left (leftward direction), and the direction (rightward direction) opposite to the leftward direction. The top (top portion, upper portion, or upper side) and the bottom (bottom portion, lower portion, or lower side) refer to the top and bottom, respective in the vertical direction. - The upward direction refers to the direction upwardly from the bottom, and a downward direction refers to the direction downwardly from the top.
- The longitudinal direction refers to the direction parallel to the rotational axis direction (axial direction) of an electrophotographic photosensitive member as an image bearing member on which a latent image is to be formed. The widthwise direction refers to a direction (orthogonal direction) perpendicularly intersecting with the longitudinal direction. One side of the longitudinal direction is the drive side, and the other end side thereof non-drive side. According the present example embodiment, a right end side in the longitudinal direction is the drive side, and a left end side thereof is the non-drive side.
- Within an image forming apparatus main body (hereinafter referred to as an apparatus main body) 100 a of the
image forming apparatus 100, the four cartridges PY, PM, PC, and PK as a first to a fourth cartridge are juxtaposed in the horizontal direction (first direction) from the back to the front side of the apparatusmain body 100 a, and attached at respective predetermined attachment positions. Theimage forming apparatus 100 employs what is called an in-line configuration or a tandem type configuration. The cartridges P are attached to positions at which the cartridges P can perform image forming operations, that is, positions at the time of image forming. - The cartridges P according to the present example embodiment are instrumental to the image forming process for forming an image on a recording material S as image forming units, and are detachably attached to the apparatus
main body 100 a of theimage forming apparatus 100. Each cartridge P according to the present example embodiment includes a drum-shaped electrophotographic photosensitive member (hereinafter referred to as a drum or photosensitive drum) 1 as an image bearing member on which a latent image is to be formed. The cartridge P is what is called an integrated process cartridge including a development unit 3 (including a developer container) as an electrophotographic image forming process unit which acts on thedrum 1. A charging device as acontact charging roller 2 is fixed to apparatusmain body 100 a according to the present example embodiment. - The
development unit 3 is a contact type or noncontact type development unit including a developingroller 3 a as a developer bearing member for supplying the developer to thedrum 1 to develop a latent image as a developer image, and adeveloper storage unit 3 b storing the developer. The color of the stored developer (hereinafter referred to as toner) differs for each cartridge P - More specifically, the first cartridge PY including the
development unit 3 storing yellow (Y) toner forms a Y color toner image on the surface of thedrum 1. The second cartridge PM including thedevelopment unit 3 storing magenta (M) toner forms an M color toner image on surface of thedrum 1. The third cartridge PC including thedevelopment unit 3 storing cyan (C) toner forms a C color toner image on the surface of thedrum 1. The fourth cartridge PK including thedevelopment unit 3 storing black (K) toner forms a K color toner image on the surface of thedrum 1. - On the front side of each of the cartridges PY, PM, PC, and PK (on the right-hand side of each cartridge P referring to
FIG. 2 ), anLED unit 11 as a light emission unit (exposure unit) for forming a latent image by exposure on the drum I of each cartridge P is disposed close to thedrum 1.FIG. 3 is an enlarged sectional view illustrating theLED unit 11. TheLED unit 11 includesLED elements 11 a, gradientindex type lenses 11 b, anelectronic substrate 11 c, and anLED unit housing 11 d. A plurality of theLED elements 11 a is disposed in the longitudinal direction, and a plurality of thelenses 11 b is disposed corresponding to theLED elements 11 a. - A plurality of the
LED elements 11 a, thelenses 11 b, and theelectronic substrate 11 c are held by theLED unit housing 11 d. An electrical conductive path is established between theelectronic substrate 11 c and thecontrol unit 200. Operations for forming a latent image on thedrum 1 are controlled by turning ON and OFF the light emission of eachLED element 11 a according to image information for each color input from theexternal host apparatus 400 to thecontrol unit 200. Light of eachLED element 11 a is condensed on eachdrum 1 through thelens 11 b to form a latent image. - A
primary transfer roller 17 is disposed below each of the cartridges PY, PM, PC, and PK to face each cartridge P. Theprimary transfer roller 17 serves as transfer member for primarily transferring a toner image on thedrum 1 to an intermediate transfer member (described below). According to the present example embodiment, the toner image primarily transferred to the intermediate transfer member is secondarily transferred to the recording material S by asecondary transfer roller 27. - An
intermediate transfer unit 12 illustrated inFIG. 2 includes a dielectric flexible endless belt (an intermediate transfer belt or a belt) 13 as an intermediate transfer member (second image bearing member, i.e., intermediate recording medium). Theintermediate transfer unit 12 further includes adrive roller 14, anauxiliary roller 15, and atension roller 16 for circularly moving thebelt 13 entrained therearound in a stretched way. - The
drive roller 14 and theauxiliary roller 15 are disposed on the back side within the apparatusmain body 100 a. Thetension roller 16 is disposed on the front side within the apparatusmain body 100 a. In a state where each cartridge P is attached at a predetermined attachment position, the undersurface of eachdrum 1 is in contact with the upper surface of the upper belt portion of thebelt 13. Inside thebelt 13, the primary transfer roller is disposed to face thedrum 1 of each cartridge across the upper belt portion. - In each cartridge P, a nip portion between the
drum 1 and thebelt 13 is a primary transfer nip portion T1. Asecondary transfer roller 27 is in contact with the drive roller across thebelt 13. A nip portion between thesecondary transfer roller 27 and thebelt 13 is a secondary transfer nip portion T2. - A
sheet feed unit 18 for storing the recording materials S to which a toner image transferred disposed below theintermediate transfer unit 12. Thesheet feed unit 18 feeds the recording materials S one by one to theintermediate transfer unit 12. Thesheet feed unit 18 includes apaper feed tray 19 for storing the stacked recording materials afeed roller 20, aseparation pad 21, and aregistration roller pair 22. Thepaper feed tray 19 can be freely loaded from the front side of the apparatusmain body 100 a (front loading). - At the upper portion on the back side within the apparatus
main body 100 a, there are disposed a fixingapparatus 23 as a fixing unit androller pair 24 for discharging the recording material S. The fixingapparatus 23 applies heat and pressure to the recording material S which bears a toner image transferred thereto, to fix the toner image to the recording material S. According to the present example embodiment, the fixingapparatus 23 includes a fixingfilm assembly 23 a and apressure roller 23 b, and the dischargingroller pair 24 includes dischargingrollers - A
door 30 as an opening/closing member for an upper opening portion of the apparatusmain body 100 a is disposed at the upper portion of the apparatusmain body 100 a. Thedoor 30 is rotatable around predetermined position as a fulcrum in the direction (first direction) in which a plurality of the cartridges P is juxtaposed. The user can detachably attach the cartridges to the apparatusmain body 100 a through the opening portion. According to the present example embodiment, a part of the upper surface of thedoor 30 functions as adischarge tray 25. - Operations for forming a full color image will be described below. In each of the first to the fourth cartridges PY, PM, PC, and PK, the drum is driven to rotate at a predetermined control speed in the direction (counterclockwise direction) indicated by the arrow illustrated in
FIG. 2 . Thebelt 13 is also driven to rotate at a speed corresponding to the speed of thedrum 1 in the clockwise direction indicated by the arrow (in a forward direction of the rotation of the drum 1). - In each cartridge P, the charging
roller 2 uniformly charges the surface of thedrum 1 to a predetermined polarity and potential at predetermined control timing, in synchronization with the driving. Then, theLED unit 11 irradiates the surface of thedrum 1 with light for exposure, according to an image signal for each color. In this way, a static electricity latent image (latent image) according to the image signal of the corresponding color is formed on the surface of eachdrum 1. The formed latent image is developed as toner image (developer image) by thedevelopment unit 3. - A Y color toner image corresponding to the Y color component of a full color image is formed on the
drum 1 of the first cartridge PY through the above-described electrophotographic image forming process operations. At the primary transfer nip portion T1 of the cartridge PY, the toner image primarily transferred to thebelt 13. An M color image corresponding the M color component of the full color image is formed on thedrum 1 of the second cartridge PM. At the primary transfer nip portion T1 of the cartridge PM, the toner image primarily transferred to the Y color toner image already transferred on thebelt 13 in a superimposed way. - A C color toner image corresponding to the C color component of the full color image is formed on the
drum 1 of third cartridge PC. At the primary transfer nip portion T1 of the cartridge PC, the toner image primarily transferred to the Y+M color toner image already transferred on thebelt 13 in a superimposed way. A K color toner image corresponding to the K color component of the full color image is formed on thedrum 1 of the fourth cartridge PK. At the primary transfer nip portion T1 of the cartridge PK, the toner image is primarily transferred to the Y+M+C color toner image already transferred on thebelt 13 in a superimposed way. - As a result, 4-color (Y+M+C+K) superimposed toner image (color image) is formed on the
belt 13 in an unfixed state. - Meanwhile, the
feed roller 20 is driven at predetermined control timing. In this way, thefeed roller 20 and theseparation pad 21 collaborate to separate and feed one sheet of the recording materials S stacked in thepaper feed tray 19. Then, theregistration roller pair 22 guides the recording material to the secondary transfer nip portion T2 at predetermined control timing. In this way, in a process in which the recording material S is conveyed through the secondary transfer nip portion T2 in a nipped state, the 4-color superimposed toner image on thebelt 13 is collectively transferred to the surface of the recording material S. - Then, the recording material S is separated from the surface of the
belt 13, guided to the fixingapparatus 23 through the conveyance path, and applied with heat and pressure at the fixing nip portion N. In this way, toner images of respective colors are mixed and fixed to the recording material S. After that, the recording material S exits the fixingapparatus 23 and is discharged onto thedischarge tray 25 as a full color image by the dischargingroller pair 24. After the recording material P is separated from thebelt 13, secondary transfer residual toner remaining on the surface of thebelt 13 is removed by acleaning unit 26. - The following describes positioning of the cartridges P, the
LED units 11, the chargingrollers 2, and theintermediate transfer unit 12 as image forming process parts relative to the apparatusmain body 100 a.FIGS. 4A and 4B illustrate the apparatusmain body 100 a when viewed from the left-hand side and the right-hand side, respectively (the exterior and drive system are not illustrated). The apparatusmain body 100 a is provided with a left substrate 101 (FIG. 4A ) and a right substrate 102 (FIG. 4B ) for supporting each roller and each unit. - The
left substrate 101 is provided with aleft holder 103, and theright substrate 102 is provided with aright holder 104. The right and theleft holders right holders LED units 11, the chargingrollers 2, and theintermediate transfer unit 12 as identical holding members, and determine the positions of these members relative to the apparatus main body and each unit. -
FIG. 5A illustrates only the left and theright holders FIG. 5B illustrates a state where theLED units 11 and the chargingrollers 2 are additionally disposed in the state illustrated inFIG. 5A , andFIG. 5C illustrates a state where theintermediate transfer unit 12 is additionally disposed in the state illustrated inFIG. 5B . TheLED units 11 are fixed to theholes 104 a of theright holder 104 corresponding to the four cartridges PY, PM, PC, and PK. - The charging
rollers 2 are rotatably supported by theholes 104 b of theright holder 104. Theleft holder 103 is also provided with hole shapes (not illustrated) similar to those of theright holder 104. These shapes also fix theLED units 11 and rotatably support the chargingrollers 2. - In the
intermediate transfer unit 12, thedrive roller 14 and thetension roller 16 are rotatably supported by theholes FIG. 5A ) on theright holder 104, respectively. Similar to theLED units 11 and the chargingrollers 2, thedrive roller 14 and thetension roller 16 are also supported by theleft holder 103. - A method for supporting the cartridges P will be described below.
FIGS. 6A and 6B illustrate a state before only a cartridge PM is attached to theright holder 104, andFIGS. 7A to 7C illustrate a state after the cartridge PM has been attached to theright holder 104.FIGS. 6A and 7A are perspective views illustrating the cartridge PM and theright holder 104, andFIGS. 6B and 7B are sectional views illustrating the cartridge PM and theright holder 104 illustrated inFIGS. 6A and 7A , respectively. - A method for holding a cartridge P will be described below by using only the cartridge PM and the
right holder 104. Similar to theLED units 11, the chargingrollers 2, and theintermediate transfer unit 12, the cartridge PM and theright holder 104 are also supported by theleft holder 103. The cartridges PY, PC, and PK are supported in a similar way to the cartridge PM. - As illustrated in
FIG. 6B , theright holder 104 is provided with U-shaped slots for positioning and inserting/extracting (attaching/detaching) a cartridge P. These slots respectively correspond to adrum shaft 1R of thedrum 1 held by the cartridge PM and aboss 3R of thedevelopment unit 3 of the cartridge PM. Two U-shaped slots for positioning and inserting/extracting (attaching/detaching) a cartridge P are provided for each color. Referring toFIG. 6B , theright holder 104 is also provided with another U-shaped slot for placing the shaft of the developingroller 3 a. This U-shaped slot is not used for positioning but for connecting to and disconnecting from the drive system (described below). - Referring to
FIG. 7B , thedrum shaft 1R of thedrum 1 held by the cartridge PM is rotatably supported by acurved surface portion 104 f of the U-shaped slot of theright holder 104, thus determining the position of thedrum 1. A U-shaped slot as an attachment/detachment passage is formed on theright holder 104 as an attachment/detachment passage forming member. Theboss 3R of thedevelopment unit 3 of the cartridge PM fits intoregulation portions 104 e as straight portions of the U-shaped slot of theright holder 104, thus regulating the rotation of the center of thedrum 1 in the cartridge PM. The above-described configuration determines the position of the cartridge PM relative to the apparatusmain body 100 a. - As described above, the positions of the cartridges P, the
LED units 11, the chargingrollers 2, and theintermediate transfer unit 12 are determined only by the left and theright holders LED units 11, the chargingrollers 2, and theintermediate transfer unit 12 related to the image forming process are common (same). - Further, the
LED units 11 do not move as in the apparatus discussed in the Japanese Patent Application Laid-Open No. 2008-296379. Therefore, there arises no positional accuracy degradation due to parts abrasion during movement, thus enabling high precision printing. Since theLED units 11 are not installed on a cover to opened to replace a cartridge as in the apparatus discussed in the Japanese Patent Application Laid-Open No. 2008-296379 but installed inside the apparatusmain body 100 a, the user can hardly touch the exposure surfaces of theLED units 11 and there is no possibility of poor exposure. - In the first to the fourth cartridges PY, PM, PC, and PK, a developer stored in the
development unit 3 is consumed as the developer is used for image formation. The apparatusmain body 100 a is provided with a method (not illustrated) for detecting the amount of remaining developer for each cartridge. - The
control unit 200 compares the detected value with a preset threshold value for life notification or warning. When the detected value of the developer remaining amount is smaller than the threshold value for a certain cartridge, thecontrol unit 200 displays the life notification or warning for the cartridge on a display unit (not illustrated). This prompts a user to ready a new cartridge in preparation for replacement or replace the cartridge to maintain the quality of output images. - Cartridge replacement operations described below.
FIG. 8A illustrates a state where thedoor 30 is opened, andFIG. 8B is a sectional view the state illustrated inFIG. 8A .FIG. 9A illustrates a state where a cartridge PM is slightly pulled out in the state illustrated inFIG. 8A , andFIG. 9B is a sectional view illustrating the state illustrated inFIG. 9A . When replacing the cartridge PM of theimage forming apparatus 100 according to the present example embodiment, the user holds ahandle 30 a and rotates thedoor 30 in the R1 direction around a doorrotational axis 30 b to open thedoor 30, as illustrated inFIGS. 8A and 8B . - Then, as illustrated in
FIGS. 9A and 9B , the user pulls the cartridge PM in the Al direction to take it out from the inside of the apparatusmain body 100 a and inserts new cartridge PM in the A2 direction to replace the cartridge. When the user opens thedoor 30, the drive of thedrum 1 and the developingroller 3 a is disconnected in synchronization with the opening. When the user closes thedoor 30, the drive is accordingly connected. When the user opens thedoor 30 and the drive of thedrum 1 and the developingroller 3 a is disconnected, the cartridge PM can be easily detached from the apparatusmain body 100 a. - The following describes configurations for opening and closing the
door 30 and for connecting and disconnecting the drive of thedrum 1 and the developingroller 3 a.FIG. 10 illustrates only thedoor 30 when opened, the cartridges P, and drive systems around the cartridges P.FIGS. 11A and 11B are enlarged views illustrating the drive system around the cartridge PK, andFIGS. 12A and 12B are sectional views illustrating the drive system illustratedFIGS. 11A and 11B .FIGS. 11A and 12A illustrate a state where thedoor 30 is closed, andFIGS. 11B and 12B illustrate a state where thedoor 30 is opened. - As illustrated in
FIG. 10 , at thedoor 30, linkarms links links main body 100 a (a supporting method is not illustrated). - Since a method for connecting and disconnecting the drive is common to the cartridges PY, PM, PC, and PK, description will be given below about the cartridge PK as a representative. As illustrated in
FIGS. 11A andFIG. 11B , thelinks arms link arms coupling cams - The
coupling cams contact coupling cams coupling cams coupling cams drive gear 161 drives thedrum 1, thedrive gear 162 drives the developingroller 3 a, and adrive gear 163 drives the charging roller 2 (a method for supporting drive gears is not illustrated). The drive gears 161 and 162 are pressed in the B direction by springs (not illustrated), and the urging forces thereof can also be transmitted to thecoupling cams - When the
door 30 is opened in this state, the state illustrated inFIG. 11A shifts to the state illustrated inFIG. 11B . At this timing, thelinks coupling cams link arms door 30 is closed, as illustrated inFIG. 12A , thecoupling cams drum 1 are in a state where acam surface 141 a contacts acam surface 151 b, and acam surface 141 b contacts acam surface 151 a. - On the other hand, when the
door 30 is opened, as illustrated inFIG. 12B , thecoupling cams cam surface 141 a contacts thecam surface 151 a. At this timing, thecoupling cam 151 and thedrive gear 161 move in the E direction (the direction opposite to the B direction) against the urging force of a spring (not illustrated), disconnecting the connection between the drum I and thedrive gear 161. This prevents the driving force from transmitting to thedrum 1. - The
coupling cams roller 3 a are configured in a similar way to the side of thedrum 1, and redundant descriptions thereof will be omitted. When thedoor 30 is opened, the driving force is not transmitted to the developingroller 3 a. - As described above, when the
door 30 is opened, the driving force to thedrum 1 and the developingroller 3 a can be disconnected, allowing the user to replace a cartridge P. - Lastly, a relation between the attachment/detachment of a cartridge P and the
LED units 11 fixed to the apparatusmain body 100 a will be described below.FIGS. 13A to 13C are enlarged sectional views illustrating a state where a cartridge P is replaced. WhileFIGS. 13A to 13C illustrate a relation between cartridge P and theright holder 104, theleft holder 103 has a similar configuration.FIG. 13A illustrates a state before a cartridge P is attached to the attachment position,FIG. 13E illustrates a state where the cartridge P is regulated to move only in two directions by theregulation portions FIG. 13C illustrates a state where the cartridge P has been attached to the attachment position. - As the cartridge P is inserted into the apparatus
main body 100 a, theboss 3R of the cartridge P and thedrum shaft 1R come in contact with theregulation portions right holder 104, respectively (the state illustrated inFIG. 13B ). When the cartridge P is inserted further, the cartridge P becomes movable only in the vertical direction illustrated inFIG. 13C . - At this timing, a relation “h1>h2” is satisfied, where h1 denotes the height from the belt 13 (
FIG. 2 ) to thedrum 1, and h2 denotes the height from thebelt 13 to theLED unit 11. Therefore, when h1<h2, the movement of the cartridge P in the B direction perpendicularly intersecting with the extraction direction A1 and the insertion direction A2 is regulated by theregulation portions drum 1 can be prevented from contacting theLED unit 11, so that the surface of thedrum 1 can be prevented from being damaged, and theLED unit 11 can be prevented from breaking down. TheLED unit 11 is disposed at a position where theLED unit 11 does not overlap with the attachment/detachment locus of thedrum 1 in the B direction perpendicularly intersecting with the extraction direction A1 and the insertion direction A2 of the cartridge P. More specifically, in a state where the insertion of the cartridge P into the apparatusmain body 100 a is completed, the rotational shaft of thedrum 1 is disposed, in the insertion direction A2 of the cartridge P, downstream from the image forming position where light emitted by theLED unit 11 forms an image the surface of thedrum 1. For this reason, even if theLED unit 11 is disposed, in the insertion direction A2, upstream from thebelt 13, it becomes possible to prevent thedrum 1 from contacting theLED unit 11, prevent the surface of the drum from being damaged, and prevent theLED unit 11 from breaking down. TheLED unit 11 is disposed at a position where theLED unit 11 does not overlap with attachment/detachment locus of thedrum 1 in the B directions Therefore, a condition “h3≥h4” is satisfied in a state where the attachment the cartridge P is completed, as illustrated inFIG. 13C , where h3 denotes the height of the rotational shaft of thedrum 1 from thebelt 13, and h4 denotes the height of the image forming position (where light from theLED unit 11 forms an image on the drum 1) from thebelt 13. The height refers to the distance from the surface of thebelt 13 to the rotational shaft or the image forming position of thedrum 1 in the normal direction on the surface of thebelt 13. - This configuration can be applied to positioning in which the
LED unit 11 is abutted against and brought into contact with thedrum 1 by using a spring (not illustrated). Even in such a configuration, the following effects are obtained: When the rotational shaft of thedrum 1 is disposed, in the insertion direction A2 of the cartridge P (a direction from the surface of thebelt 13 toward thedrum 1 in the normal direction of the belt 13), downstream from the image forming position where light emitted by theLED unit 11 forms an image on the surface of thedrum 1, theLED unit 11 does not contact the portion of thedrum 1 having the largest radius at time of inserting or extracting a cartridge P. Therefore, when a cartridge P is inserted or extracted, it is possible to reduce a time period during which the urging force of the spring (not illustrated) serves as a resistance to the attachment and detachment of a cartridge P, or the distance of the cartridge P. The fact that theLED unit 11 does not contact the portion of thedrum 1 having the largest radius means that it is possible to reduce the distance over which theLED unit 11 is moved against the urging force of the spring (not illustrated) when inserting or extracting a cartridge P. Accordingly, when inserting or extracting a cartridge P, it is possible to reduce the maximum value of e resistance exerted on the cartridge P by the spring (not illustrated). - Further, regulating the cartridge P to a certain extent improves usability. When the user starts the insertion of the cartridge P into the apparatus
main body 100 a (the state illustrated inFIG. 13A ), the user can insert the cartridge P while freely moving it. Then, after the user has inserted the cartridge P into the apparatusmain body 100 a to certain extent, the position of the cartridge P can be guided to the attachment position (the state illustrated inFIG. 13B ). - The cartridge P is stopped at the attachment position where an image is formed on the drum (the state illustrated in 13C). Therefore, according to the present example embodiment, it is possible to achieve high usability and a configuration for inserting/extracting (attaching/detaching) a cartridge P without causing a damage to the cartridge P and the
LED unit 11 when inserting a cartridge P. - According to the present example embodiment, as described above, it is possible to pro de an image forming apparatus capable of achieving both apparatus downsizing and high precision printing by using a light emission unit having a plurality of light emitting elements in a case where an opening/closing member is disposed at an upper portion of the apparatus in a vertical direction. More specifically, compared with a case where a light scanning apparatus (scanner) is used, the present example embodiment enables the apparatus downsizing by disposing an LED array as a light emission unit close to the
photosensitive drum 1. This because the LED array produces a lower light quantity than a scanner, and a gradient index type lens for collecting LED light has a short focal length. In addition, high precision printing can be achieved by fixing the light emission unit to the inside of the apparatusmain body 100 a, unlike the apparatus discussed in Japanese Patent Application Laid-Open No. 2008-296379. - Further, high precision printing can be guaranteed by such positioning that the cartridge P does not hit the light emission unit fixed to the apparatus
main body 100 a when attaching/detaching a cartridge P including thedrum 1. - A second example embodiment of the present disclosure will be described below with reference to
FIGS. 19 to 23A to 23C . According to the first example embodiment, the cartridge (first cartridge) including thedrum 1 does not include the chargingroller 2. According to the present example embodiment, the cartridge (first cartridge) including thedrum 1 includes the chargingroller 2. Other configurations are similar to those according to the first example embodiment. -
FIG. 19 is a perspective view illustrating a cartridge P having a configuration according to the present example embodiment. Similar to the first example embodiment, the cartridge P is provided with thedrum 1 and the developingroller 3 a. The cartridge P is also provided with the chargingroller 2 as an additional member. More specifically, the chargingroller 2 is rotatably supported in adevelopment unit 301 including the developingroller 3 a, and is rotatably driven along with the rotation of thedrum 1. - A method for positioning the cartridges P, the
LED units 11, and theintermediate transfer unit 12 as image forming process parts relative to the apparatusmain body 100 a will be described below.FIG. 20A illustrates only left and theright holders FIG. 20B illustrates a state where theLED units 11 are disposed in additionFIG. 20A , andFIG. 20C illustrates a state where theintermediate transfer unit 12 is disposed in addition toFIG. 20B . Similar to the first example embodiment, the left and theright holders right substrates - The
LED units 1 are fixed to theholes 304 a of theright holder 304 corresponding to the four cartridges PY, PM, PC, and PK. Similar to theright holder 304, theleft holder 303 is also provided with hole shapes (not illustrated), and theLED units 11 are fixed to theleft holder 303. - In the
intermediate transfer unit 12, thedrive roller 14 and thetension roller 16 are rotatably supported in theholes right holder 304. Similar to theLED units 11, thedrive roller 14 and thetension roller 16 are also supported in theleft holder 303. - A method for supporting a cartridge P will be described below.
FIGS. 21A and 12B illustrate a state where only a cartridge PM is attached to theright holder 304.FIG. 21A is a perspective view illustrating the cartridge PM and theright holder 304, andFIG. 21B is a sectional view illustrating the cartridge PM and theright holder 304 illustrated inFIG. 21A . The method for supporting the cartridge P will be described below based only on the cartridge PM and theright holder 304. However, same as theLED units 11 and theintermediate transfer unit 12, the cartridge PM is similarly supported in theleft holder 303. The cartridges PY, PC, and PK are supported in a way similar to the cartridge PM. - The
right holder 304 is provided with U-shaped slots for positioning and attaching/detaching a cartridge P corresponding to thedrum shaft 1R of thedrum 1 held in the cartridge PM and aboss 301R of thedevelopment unit 301 of the cartridge PM. Two U-shaped slots for positioning and inserting/extracting (attaching/detaching) a cartridge are provided for each color. Theright holder 304 is also provided with another U-shaped slot for placing the shaft of the developingroller 3 a. This U-shaped slot is not used for positioning but for connecting to and disconnecting from the drive system. - The
drum shaft 1R of the drum held by the cartridge PM is rotatably supported incurved surface portion 304 f of the U-shaped slot of theright holder 304, thus determining the position of thedrum 1. Theboss 301R of thedevelopment unit 301 of the cartridge PM fits intoregulation portions 304 e as straight portions of the U-shaped slot of theright holder 304, thus regulating the rotation of the center of thedrum 1 in the cartridge PM. - In this way, the position of the cartridge PM relative to the apparatus
main body 100 a is determined. Configurations for opening and closing thedoor 30 and for connecting and disconnecting the drive of thedrum 1 and the developingroller 3 a are similar to those according to first example embodiment, and redundant descriptions thereof will be omitted. - Lastly, a relation between the
LED units 11 fixed to the apparatusmain body 100 a and the attachment/detachment of a cartridge P will be described below. According to the present example embodiment, the cartridge P holds the chargingroller 2. Because of the image forming process, the chargingroller 2 needs to be disposed on the upstream side of theLED unit 11 in contact with thedrum 1. Since theLED unit 11 needs to be disposed close to thedrum 1 as described above, theLED unit 11 and the chargingroller 2 are disposed in a positional relation as illustrated inFIG. 22 .FIG. 22 illustrates an area where light of theLED unit 11 is projected on thebelt 13, and the chargingroller 2 is disposed within the area. - More specifically, when projecting the light of the
LED unit 11 in the second direction (vertical direction) connecting the center position of thedrum 1 and the center position of thetransfer roller 17 at the time of image formation within a section perpendicularly intersecting with the rotational shaft of thedrum 1, the chargingroller 2 exists as a part of a charge member in the area on which the light of theLED unit 11 is projected. This means that the cartridge P cannot inserted/extracted (attached/detached) in one direction as in first example embodiment. Therefore, it is necessary to insert the cartridge P into the apparatusmain body 100 a while getting the chargingroller 2 into under theLED unit 11. - A specific method is illustrated in
FIGS. 23A to 23C .FIGS. 23A to 23C are enlarged sectional views illustrating a state where the cartridge P is replaced. WhileFIGS. 23A to 23C illustrate a relation between the cartridge P and theright holder 304, theleft holder 303 also has a similar configuration.FIG. 23A illustrates a state before a cartridge P is attached to the attachment position,FIG. 23B illustrates a state where the cartridge P is regulated to move only 1n two directions byregulation portions FIG. 23C illustrates a state where the cartridge P has been attached to the attachment position. - As the cartridge P is inserted into the apparatus
main body 100 a, thedrum shaft 1R of thedrum 1 held by the cartridge PM enters theregulation portion 304 f of theright holder 304, into a first area. In the first area, an attachment/detachment passage has the vertical direction (second direction) as an attachment/detachment direction. As the cartridge P is further inserted, theboss 301R of the cartridge P and thedrum shaft 1R come in contact with theregulation portions right holder 304, respectively (the state illustrated inFIG. 23B ). - As the cartridge P is still further inserted, the cartridge P becomes movable only in the J and K directions illustrated in
FIG. 23B . More specifically, theright holder 304 is provided with second area as an attachment/detachment passage connecting with the first area. The second area has a direction (third direction) intersecting with the vertical direction (second direction) as an attachment/detachment direction. - Thus, the insertion/extraction direction of the cartridge P is regulated using the
regulation portions drum 1 and the chargingroller 2 can be prevented from contacting theLED unit 11. This regulation prevents the surfaces of thedrum 1 and the chargingroller 2 from being damaged and prevents theLED unit 11 from breaking down. - Further, regulating the cartridge P to a certain extent improves usability. When the user starts the insertion of the cartridge P into the apparatus
main body 100 a (the state illustrated inFIG. 22A ), the user can insert the cartridge P while freely moving it. Then, when the user has inserted the cartridge P into the apparatusmain body 100 a to certain extent, the position of the cartridge P can be guided to the attachment position (the state illustrated inFIG. 23B ). - Then, the cartridge P is stopped at the attachment posit on where an image is formed on the drum 1 (the state illustrated in
FIG. 23C ). Therefore, according to the present example embodiment, is possible achieve a configuration showing high usability for inserting/extracting a cartridge P without causing a damage to the cartridge P and theLED unit 11 when inserting a cartridge P. - In the above-described configuration according to present example embodiment, a charge member is integrally formed with a cartridge P to limit the locus of the
photosensitive drum 1 and the chargingroller 2. This limitation prevents them from contacting theLED unit 11, so that the insertion/extraction (attachment/detachment) of a cartridge P can be achieved. - This configuration makes it possible to provide an image forming apparatus capable of achieving both apparatus downsizing and high precision printing by using a light emission unit having a plurality of light emitting elements while an opening/closing member is disposed at an upper portion of the apparatus in a vertical direction. More specifically, compared with case where a light scanning apparatus (scanner) is used, the present example embodiment enables apparatus downsizing by disposing an LED array as a light emission unit close to the
photosensitive drum 1. High precision printing is enabled by fixing the light emission unit to the inside of the apparatusmain body 100 a, unlike the apparatus discussed in Japanese Patent Application Laid-Open No. 2008-296379. - Further, high precision printing can guaranteed by positioning the cartridge P such that it does not hit the light emission unit fixed to the apparatus
main body 100 a when attaching/detaching a cartridge P which includes thedrum 1 and the chargingroller 2. - While the present disclosure has specifically been described based on the above-described preferred example embodiments, the present disclosure not limited thereto but can be modified in various ways within the ambit of the appended claims.
- The image forming apparatuses according to the above-described example embodiments include the
transfer rollers 17 for primarily transferring toner images to an intermediate transfer member (intermediate transfer belt), and thesecondary transfer roller 27 for secondarily transferring to a recording material the toner image primarily transferred to the intermediate transfer member. However, the present disclosure is not limited thereto. An image forming apparatus may not include thesecondary transfer roller 27 as illustrated inFIG. 14 , and may directly transfer toner images to a recording material conveyed by a conveyance belt, by using thetransfer rollers 17. While this configuration is applicable not only to the first example embodiment but also to the second example embodiment, a modification of the first example embodiment will be illustrated inFIG. 14 as a representative. - Referring to the modification illustrated in
FIG. 14 , other than aconveyance unit 212, configurations and operations are similar to those according to the first example embodiment illustrated inFIG. 2 , and redundant descriptions thereof will be omitted. In theconveyance unit 212, unlike theconveyance unit 12 illustrated inFIG. 2 , thedrive roller 14 and thetension roller 16 move aconveyance belt 213 in circles in a stretched way. The recording material S conveyed from thesheet feed unit 18 is conveyed from the front side to the back side by theconveyance belt 213. Then, toner images are sequentially transferred from the fourcartridges 2 to the recording material S, thus forming an image. - The process of forming a toner image on the
drum 1 of a cartridge P is similar to the process illustrated inFIG. 2 . Similar to the recording material S inFIG. 2 , the recording material S with toner images transferred thereto passes through the fixingapparatus 23 and the dischargingroller pair 24, and then is stacked on thedischarge tray 25. As illustrated inFIGS. 15A and 15B , the modification illustrated inFIG. 14 allows the user to perform cartridge replacement in the same way as illustrated inFIGS. 9A and 9B . - While, in the above-described example embodiments, the
drum 1 and adevelopment unit 203 are integrally formed as a process cartridge, the present disclosure is not limited thereto. More specifically, as illustrated inFIGS. 16A, 16B, and 17 , the second cartridge including thedevelopment unit 203 may be separated relative to the first cartridge including thedrum 1. - In positioning of the
development unit 203 in this case, as illustrated inFIG. 17 aboss 203R of thedevelopment unit 203 is rotatably supported by acurved surface portion 204 f of the U-shaped slot of aright holder 204. The urging force of aspring 250 disposed in the apparatusmain body 100 a causes apressing cam 251 to pressdevelopment unit 203 to the left. Since thedevelopment unit 203 is pressed by the urging force of thespring 250, the developingroller 3 a can be pressed onto thedrum 1. - In this case, the
pressing cam 251 is configured to be movable only in the lateral direction illustrated inFIG. 17 . When thedoor 30 is closed, as illustrated inFIG. 17 , thepressing cam 251 presses thedevelopment unit 203. When thedoor 30 is opened, thepressing cam 251 stops pressing thedevelopment unit 203. The left holder (not illustrated) is also configured in a similar way to the above-describedright holder 204. - While, in the above-described example embodiments, the charging
roller 2 serves as a charge member in contact with thedrum 1, a corona charging 222 can also be used as a charge member, which does not contact thedrum 1, as illustrated inFIG. 18 . - While, in the above-described example embodiments, an LED is used as a light emitting element, other light emitting elements can also be used.
- While the present disclosure has been described with reference to example embodiments, it is to understood that the disclosure is not limited to the disclosed example embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
- This application claims the benefit of Japanese Patent Application No. 2017-033246, filed Feb. 24, 2017, which is hereby incorporated by reference herein in its entirety.
Claims (7)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2017033246A JP6946017B2 (en) | 2017-02-24 | 2017-02-24 | Image forming device |
JP2017-033246 | 2017-02-24 |
Publications (2)
Publication Number | Publication Date |
---|---|
US20180246466A1 true US20180246466A1 (en) | 2018-08-30 |
US10459401B2 US10459401B2 (en) | 2019-10-29 |
Family
ID=63245357
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US15/898,054 Active US10459401B2 (en) | 2017-02-24 | 2018-02-15 | Image forming apparatus |
Country Status (2)
Country | Link |
---|---|
US (1) | US10459401B2 (en) |
JP (1) | JP6946017B2 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20220236686A1 (en) * | 2021-01-28 | 2022-07-28 | Kyocera Document Solutions Inc. | Image forming apparatus requiring less external force to move cover member from open state |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP7452073B2 (en) | 2020-02-19 | 2024-03-19 | ブラザー工業株式会社 | image forming device |
Family Cites Families (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR940005153B1 (en) * | 1991-04-22 | 1994-06-11 | 삼성전자 주식회사 | Image formation device in led printer |
US5729809A (en) * | 1995-06-16 | 1998-03-17 | Konica Corporation | Color image forming apparatus with intermediate transfer |
US6134403A (en) * | 1996-10-14 | 2000-10-17 | Konica Corporation | Color image forming apparatus having developing devices located within a central angle of 180° |
JP2001356548A (en) * | 2000-06-14 | 2001-12-26 | Brother Ind Ltd | Color image forming device |
JP3959601B2 (en) * | 2001-09-28 | 2007-08-15 | セイコーエプソン株式会社 | Color image forming apparatus |
US7395008B2 (en) * | 2003-02-24 | 2008-07-01 | Brother Kogyo Kabushiki Kaisha | Image formation apparatus and photoreceptor cartridge |
JP4059110B2 (en) | 2003-03-13 | 2008-03-12 | ブラザー工業株式会社 | Image forming apparatus |
JP3945437B2 (en) | 2003-03-28 | 2007-07-18 | ブラザー工業株式会社 | Image forming apparatus |
JP4667180B2 (en) * | 2005-09-09 | 2011-04-06 | キヤノン株式会社 | Image forming apparatus |
JP4423567B2 (en) * | 2006-06-08 | 2010-03-03 | ブラザー工業株式会社 | Image forming apparatus |
JP4345802B2 (en) | 2006-11-07 | 2009-10-14 | ブラザー工業株式会社 | Multicolor image forming apparatus |
JP2008158381A (en) | 2006-12-26 | 2008-07-10 | Brother Ind Ltd | Image forming apparatus |
JP4552967B2 (en) | 2007-05-29 | 2010-09-29 | ブラザー工業株式会社 | Image forming apparatus |
JP5321629B2 (en) * | 2011-03-30 | 2013-10-23 | ブラザー工業株式会社 | Image forming apparatus |
JP6112394B2 (en) * | 2012-05-01 | 2017-04-12 | 株式会社リコー | Image forming apparatus and process cartridge used therefor |
JP2014224858A (en) * | 2013-05-15 | 2014-12-04 | 株式会社リコー | Image forming apparatus |
-
2017
- 2017-02-24 JP JP2017033246A patent/JP6946017B2/en active Active
-
2018
- 2018-02-15 US US15/898,054 patent/US10459401B2/en active Active
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20220236686A1 (en) * | 2021-01-28 | 2022-07-28 | Kyocera Document Solutions Inc. | Image forming apparatus requiring less external force to move cover member from open state |
US11609531B2 (en) * | 2021-01-28 | 2023-03-21 | Kyocera Document Solutions Inc. | Image forming apparatus requiring less external force to move cover member from open state |
Also Published As
Publication number | Publication date |
---|---|
US10459401B2 (en) | 2019-10-29 |
JP6946017B2 (en) | 2021-10-06 |
JP2018138954A (en) | 2018-09-06 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US7894733B2 (en) | Process cartridge and image forming apparatus | |
US9002230B2 (en) | Electrophotographic color image forming apparatus with movable cartridge carrying member and associated electrical contacts | |
US7567769B2 (en) | Electrophotographic color image forming apparatus | |
US8213828B2 (en) | Electrophotographic image forming apparatus and process cartridge mounted thereto having contacts electrically connecting with an electrical contact | |
US8532557B2 (en) | Attachment assist device and image forming apparatus including same | |
KR20130011251A (en) | Developing cartridge and image forming apparatus having the same | |
US10261467B2 (en) | Image forming apparatus | |
US9069325B2 (en) | Image forming apparatus | |
CN112526856B (en) | Cartridge and image forming apparatus | |
US20130209138A1 (en) | Electrophotographic image forming apparatus | |
US10459401B2 (en) | Image forming apparatus | |
KR20180011005A (en) | Image forming apparatus | |
US20130107282A1 (en) | Image forming apparatus | |
US8538290B2 (en) | Image forming apparatus with detachable constituent component and holding part | |
JP2021140070A (en) | Image forming apparatus | |
JP2022048496A (en) | Image forming apparatus | |
JP2006151620A (en) | Roller pair unit, carrying device, and image forming device | |
KR20210032915A (en) | Cartridge and image forming apparatus |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
FEPP | Fee payment procedure |
Free format text: ENTITY STATUS SET TO UNDISCOUNTED (ORIGINAL EVENT CODE: BIG.); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY |
|
AS | Assignment |
Owner name: CANON KABUSHIKI KAISHA, JAPAN Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:HIJIKATA, SHUNSUKE;INABA, YUICHIRO;WATANABE, TOSHIYUKI;REEL/FRAME:046040/0761 Effective date: 20180205 |
|
STPP | Information on status: patent application and granting procedure in general |
Free format text: FINAL REJECTION MAILED |
|
STPP | Information on status: patent application and granting procedure in general |
Free format text: DOCKETED NEW CASE - READY FOR EXAMINATION |
|
STPP | Information on status: patent application and granting procedure in general |
Free format text: NOTICE OF ALLOWANCE MAILED -- APPLICATION RECEIVED IN OFFICE OF PUBLICATIONS |
|
STPP | Information on status: patent application and granting procedure in general |
Free format text: PUBLICATIONS -- ISSUE FEE PAYMENT VERIFIED |
|
STCF | Information on status: patent grant |
Free format text: PATENTED CASE |
|
MAFP | Maintenance fee payment |
Free format text: PAYMENT OF MAINTENANCE FEE, 4TH YEAR, LARGE ENTITY (ORIGINAL EVENT CODE: M1551); ENTITY STATUS OF PATENT OWNER: LARGE ENTITY Year of fee payment: 4 |